私有方法七

 /**
     * @author : lKF35745
     * @version: 1.0
     * <p>时间 : 2011-1-18</p>
     * <p>描述 : 获取DstScreen的所有父节点会议ID（包括自己）</p>
     * <p>Copyright 1988-2005, Huawei Tech. Co., Ltd.</p>
     * @return List<String> 会议集合列表
     */
    private List<String> getDstScreenParentConferID(
            CascadeTopoTree cascadeTree, String dstScreenConferID)
    {
        if (logger.isDebugEnabled())
        {
            logger.debug("begin to getDstScreenParentConferID and ConferID is "
                    + dstScreenConferID);
        }
        
        //得到DstScreen视频源的所有父节点会议ID
        List<String> dstScreenParentConferID = findParentNodeByConferenceID(
                dstScreenConferID, cascadeTree);
        if (null == dstScreenParentConferID
                || dstScreenParentConferID.size() < 1)
        {
            logger.warn("this dstScreenParentConferID List is empty ");
            return null;
        }
        if (logger.isDebugEnabled())
        {
            logger.debug("end to getDstScreenParentConferID and result size is"
                    + dstScreenParentConferID.size());
        }
        return dstScreenParentConferID;
    }